/* jcifs msrpc client library in Java
 * Copyright (C) 2006  "Michael B. Allen" <jcifs at samba dot org>
 *                     "Eric Glass" <jcifs at samba dot org>
 * 
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 * 
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 * 
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

package jcifs.dcerpc;

import java.io.*;
import java.net.*;
import java.security.Principal;

import jcifs.smb.NtlmPasswordAuthentication;
import jcifs.util.Hexdump;
import jcifs.dcerpc.ndr.NdrBuffer;

public abstract class DcerpcHandle implements DcerpcConstants {

    /* Bindings are in the form:
     * proto:\\server[key1=val1,key2=val2]
     * or
     * proto:server[key1=val1,key2=val2]
     * or
     * proto:[key1=val1,key2=val2]
     *
     * If a key is absent it is assumed to be 'endpoint'. Thus the
     * following are equivalent:
     * proto:\\ts0.win.net[endpoint=\pipe\srvsvc]
     * proto:ts0.win.net[\pipe\srvsvc]
     *
     * If the server is absent it is set to "127.0.0.1"
     */ 
    protected static DcerpcBinding parseBinding(String str) throws DcerpcException {
        int state, mark, si;
        char[] arr = str.toCharArray();
        String proto = null, key = null;
        DcerpcBinding binding = null;

        state = mark = si = 0;
        do {
            char ch = arr[si];

            switch (state) {
                case 0:
                    if (ch == ':') {
                        proto = str.substring(mark, si);
                        mark = si + 1;
                        state = 1;
                    }
                    break;
                case 1:
                    if (ch == '\\') {
                        mark = si + 1;
                        break;
                    }
                    state = 2;
                case 2:
                    if (ch == '[') {
                        String server = str.substring(mark, si).trim();
                        if (server.length() == 0)
                            server = "127.0.0.1";
                        binding = new DcerpcBinding(proto, str.substring(mark, si));
                        mark = si + 1;
                        state = 5;
                    }
                    break;
                case 5:
                    if (ch == '=') {
                        key = str.substring(mark, si).trim();
                        mark = si + 1;
                    } else if (ch == ',' || ch == ']') {
                        String val = str.substring(mark, si).trim();
                        if (key == null)
                            key = "endpoint";
                        binding.setOption(key, val);
                        key = null;
                    }
                    break;
                default:
                    si = arr.length;
            }

            si++;
        } while (si < arr.length);

        if (binding == null || binding.endpoint == null)
            throw new DcerpcException("Invalid binding URL: " + str);

        return binding;
    }

    protected DcerpcBinding binding;
    protected int max_xmit = 4280;
    protected int max_recv = max_xmit;
    protected int state = 0;
    protected DcerpcSecurityProvider securityProvider = null;
    private static int call_id = 1;

    public static DcerpcHandle getHandle(String url,
                NtlmPasswordAuthentication auth)
                throws UnknownHostException, MalformedURLException, DcerpcException {
        if (url.startsWith("ncacn_np:")) {
            return new DcerpcPipeHandle(url, auth);
        }
        throw new DcerpcException("DCERPC transport not supported: " + url);
    }

    public void bind() throws DcerpcException, IOException {
synchronized (this) {
        try {
            state = 1;
            DcerpcMessage bind = new DcerpcBind(binding, this);
            sendrecv(bind);
        } catch (IOException ioe) {
            state = 0;
            throw ioe;
        }
}
    }
    public void sendrecv(DcerpcMessage msg) throws DcerpcException, IOException {
        byte[] stub, frag;
        NdrBuffer buf, fbuf;
        boolean isLast, isDirect;
        DcerpcException de;

        if (state == 0) {
            bind();
        }

        isDirect = msg instanceof DcerpcBind;

        stub = jcifs.smb.BufferCache.getBuffer();
        try {
            int off, tot, n;

            buf = new NdrBuffer(stub, 0);

            msg.flags = DCERPC_FIRST_FRAG | DCERPC_LAST_FRAG;
            msg.call_id = call_id;

            msg.encode(buf);

            if (securityProvider != null) {
                buf.setIndex(0);
                securityProvider.wrap(buf);
            }

            tot = buf.getLength();
            off = 0;

            while (off < tot) {
                msg.call_id = call_id++;

                if ((tot - off) > max_xmit) {
                    /* Multiple fragments. Need to set flags and length
                     * and re-encode header
                    msg.length = n = max_xmit;
                    msg.flags &= ~DCERPC_LAST_FRAG;
                    buf.start = off;
                    buf.reset();
                    msg.encode_header(buf);
                     */
                    throw new DcerpcException("Fragmented request PDUs currently not supported");
                } else {
                    n = tot - off;
                }

                doSendFragment(stub, off, n, isDirect);
                off += n;
            }

            doReceiveFragment(stub, isDirect);
            buf.reset();
            buf.setIndex(8);
            buf.setLength(buf.dec_ndr_short());

            if (securityProvider != null)
                securityProvider.unwrap(buf);

            buf.setIndex(0);

            msg.decode_header(buf);

            off = 24;
            if (msg.ptype == 2 && msg.isFlagSet(DCERPC_LAST_FRAG) == false)
                off = msg.length;

            frag = null;
            fbuf = null;
            while (msg.isFlagSet(DCERPC_LAST_FRAG) == false) {
                int stub_frag_len;

                if (frag == null) {
                    frag = new byte[max_recv];
                    fbuf = new NdrBuffer(frag, 0);
                }

                doReceiveFragment(frag, isDirect);
                fbuf.reset();
                fbuf.setIndex(8);
                fbuf.setLength(fbuf.dec_ndr_short());

                if (securityProvider != null)
                    securityProvider.unwrap(fbuf);

                fbuf.reset();
                msg.decode_header(fbuf);
                stub_frag_len = msg.length - 24;

                if ((off + stub_frag_len) > stub.length) {
                    // shouldn't happen if alloc_hint is correct or greater
                    byte[] tmp = new byte[off + stub_frag_len];
                    System.arraycopy(stub, 0, tmp, 0, off);
                    stub = tmp;
                }

                System.arraycopy(frag, 24, stub, off, stub_frag_len);
                off += stub_frag_len;
            }

            buf = new NdrBuffer(stub, 0);
            msg.decode(buf);
        } finally {
            jcifs.smb.BufferCache.releaseBuffer(stub);
        }

        if ((de = msg.getResult()) != null)
            throw de;
    }

    public void setDcerpcSecurityProvider(DcerpcSecurityProvider securityProvider)
    {
        this.securityProvider = securityProvider;
    }
    public String getServer() {
        if (this instanceof DcerpcPipeHandle)
            return ((DcerpcPipeHandle)this).pipe.getServer();
        return null;
    }
    public Principal getPrincipal() {
        if (this instanceof DcerpcPipeHandle)
            return ((DcerpcPipeHandle)this).pipe.getPrincipal();
        return null;
    }
    public String toString() {
        return binding.toString();
    }

    protected abstract void doSendFragment(byte[] buf,
                int off,
                int length,
                boolean isDirect) throws IOException;
    protected abstract void doReceiveFragment(byte[] buf, boolean isDirect) throws IOException;
    public abstract void close() throws IOException;
}
